Guest Post by Willis Eschenbach
In early 2013, the US Energy Information Agency (EIA) released their new figures for the “levelized cost” of new power plants. I just came across them, so I thought I’d pass them on. These are two years more recent than the same EIA cost estimates I discussed in 2011 here. Levelized cost is the average cost of power from a new generating plant over its entire lifetime of service. The use of levelized cost allows us to compare various energy sources on an even basis. Here are the levelized costs of power by fuel source, for plants with construction started now that would enter service in 2018:
Figure 1. The levelized cost of new power plants that would come on line in 2018. They are divided into dispatchable (blue bars, marked “D:”) and non-dispatchable power sources (gray bars, marked “N:”).
Now, there are two kinds of electric power sources. Power sources that you can call on at any time, day or night, are called “dispatchable”. These are shown in blue above, and include nuclear, geothermal, fossil fuel, and the like. They form the backbone of the generation mix.
On the other hand, intermittent power sources are called “non-dispatchable”. They include wind and solar. Hydro is an odd case, because typically, for part of the year it’s dispatchable, but in the dry season it may not be. Since it’s only seasonally dispatchable, I’ve put it with the non-dispatchable sources.
OK, first rule of the grid. You need to have as much dispatchable generation as is required by your most extreme load, and right then. The power grid is a jealous bitch, there’s not an iota of storage. When the demand rises, you have to meet it immediately, not in a half hour, or the system goes down. You need power sources that you can call on at any time.
You can’t depend on solar or wind for that, because it might not be there when you need it, and you get grid brownout or blackout. Non-dispatchable power doesn’t cut it for that purpose.
This means that if your demand goes up, even if you’ve added non-dispatchable power sources like wind or solar to your generation mix, you still need to also add dispatchable power equal to the increased demand.
So there are two options. If the demand goes up, either you have to add more dispatchable power, or you can choose to add both more dispatchable power and more non-dispatchable power. Guess which one is more expensive …
And that, in turn means that the numbers above are deceptive—when demand goes up, as it always does, if you add a hundred megawatts of wind at $0.09 per kWh to the system, you also need to add a hundred megawatts of natural gas or geothermal or nuclear to the system.
As a result, for all of the non-dispatchable power sources, those gray bars in Figure 1, you need to add at least seven cents per kilowatt-hour to the prices shown there, so you’ll have dispatchable power when you need it. Otherwise, the electric power will go out, and you’ll have villagers with torches … and pitchforks …
Finally, I’m not sure I believe the maintenance figures in their report about wind. For solar, they put the price of overhead and maintenance at about one cent per kilowatt-hour. OK, that seems fair enough, there are no moving parts at all, just routine cleaning the dust off the panels.
But then, they say that the overhead and maintenance costs for wind are only one point three cents per kilowatt-hour, just 30% more than solar … sorry, that won’t wash. With wind, you have a multi-tonne complex piece of rapidly rotating machinery, sitting on a monstrous bearing way up on top of a huge pipe, with giant propellors attached to it, hanging out where the strongest winds blow. I’m not believing that the maintenance on that monstrosity will cost only 30% more than dusting photovoltaic panels …
Best to all,
Usual Request: If you disagree with what I or someone else says, please QUOTE THE EXACT WORDS you disagree with. That allows everyone to understand exactly what you are objecting to.